This application relates to a vehicle key fob having a detachable key for use by a valet parking attendant. Further, this invention relates to a key fob which assists an operator in locating a vehicle when parked.
Modern vehicles are typically provided with a key fob providing a number of electronic control functions. Typical key fob functions include door lock/unlock, trunk lock/unlock, and various other security controls. As more and more controls are incorporated into a vehicle key fob, certain common uses of a vehicle key become problematic. As one example, when parking at a restaurant, etc., an operator often chooses to allow a parking valet to utilize the key to park the vehicle. If the valet is allowed to have complete use of all of the key fob functions, then security of the vehicle might be compromised.
Various attempts have been made to limit the number of controls available to a valet. However, each of these attempts have been unduly complex. It would be desirable to provide a simple key and key fob combination wherein the valet is allowed use of the key for driving and parking a vehicle, but not allowed access to all of the security functions on the key fob.
One other problem with modern vehicles is locating the vehicle in large parking areas. Often, an operator will spend a good deal of time attempting to locate a vehicle in a large parking lot. One known way of locating a vehicle uses a key fob. The user presses the lock button on the key fob. The lock button actuates a sound, provided the key fob is within a predetermined distance of the vehicle. When the sound is made, the operator can look in the direction of the sound and hopefully find the vehicle. However, this method does require the operator to be within a short distance of the vehicle, and thus does not address the problem of finding a vehicle in a very large parking area.
In one feature of this invention, a key is held in its key fob by a retention feature, and specifically latches. The key easily and quickly snaps into the key fob, and is easily removed by actuation of the latches. Thus, the operator can remove the key from the key fob, and can provide the key to the valet parking attendant.
Moreover, the key by itself preferably has fewer controls for security applications than does the key fob. As an example, while the key fob may have door unlock/lock functions and trunk lock/unlock functions, the key may be solely a mechanical key which can be utilized for mechanically opening a door and then starting the vehicle, but which has no control function. Alternatively, the key may have a single button for locking/unlocking the doors, but does not provide access to the trunk.
In a preferred feature of this invention, the key fob is provided with a sensor which senses when the key has been removed. When the key is removed, the sensor sends a signal to a control, and the control preferably moves the vehicle into a xe2x80x9cvaletxe2x80x9d mode. In the valet mode, the trunk is preferably locked, and preferably not allowed to open from the mechanical key. Similarly, the glove compartment is locked and not allowed to open by the mechanical key. Thus, the valet is not allowed access to secured areas in the vehicle. Further, other controls such as limiting the RPMs on the engine may also be actuated by the key fob when the key has been removed.
In a further separate feature of this invention, the combined key and key fob have a vehicle locator function. The key fob is provided with both a transmitter and receiver, as is commonly known. The transmitter transmits a signal to the vehicle, and a vehicle will send back an answering signal for identification purposes. The vehicle based receivers can make an estimate of distance based upon the strength of the signal received from the key fob.
In a disclosed embodiment of this invention, a receiver on a vehicle receives a signal from a key fob, and makes a determination of whether the particular key is inside or outside of a predetermined distance. If the particular key is close to the vehicle and inside the predetermined distance then the receiver on the vehicle interprets the signal to be a control signal from the key. As an example, the key fob may have its door unlock key actuated, and if it is within a predetermined distance, then the control will unlock the vehicle doors. However, if the signal is outside of the distance, then the vehicle receiver will interpret the signal as being a car locator request. In car locator mode, the vehicle sends a signal back to the key fob which will provide the key fob with an indication of the approximate direction to the vehicle.
In one preferred method, the key fob is swept through an angular range while holding a button, such as the door unlock button actuated. The signal from the key fob is received by the vehicle for which the operator is searching. The vehicle receiver determines that the signal is from a key fob outside the predetermined distance, and thus determines that the key fob is in a xe2x80x9clocatorxe2x80x9d mode. A signal is sent back to the key fob. As the key fob is swept through the angular range, a receiver on the key fob receives the signal from the vehicle. The signal received at the fob will be of varying strength as the key fob receiver is pointed away from and directly toward the vehicle. After a first sweep through the range is complete, the key is returned through the same range. The control has previously stored the approximate peak signal value from the vehicle received by the key fob. On the second sweep back, when this same peak signal is approached, a signal on the key fob is actuated to allow the operator to identify the approximate direction of the vehicle. Alternatively, once the key fob and vehicle are in the locator mode, the vehicle can sense the strength of the signal as the key fobs moves through the sweep. The vehicle can then identify a peak, and when that peak is again sensed, send a directional signal to the key fob. When the key fob receives the signal, it can then actuate the locator device. The signal can be light, sound, vibration, etc.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.